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Biomedical subjects

K J Doyle

Publications and source records attributed to K J Doyle.

36 records · Page 2Linked to original sources
PubMed1995

Congenital aural cholesteatoma: results of surgery in 60 cases.

From 1978 to 1993, 59 patients (60 ears) with congenital middle ear cholesteatoma were treated at the House Ear Clinic. The median patient age at presentation was 5 years, and the period of postoperative follow-up was 4.8 years. An intact canal wall was maintained in 58 of 60 cases and a closed middle ear space in all cases. In 12 operations, lateral graft tympanoplasty eradicated the cholesteatoma in one stage; 32 patients required a second-stage surgery to rule out recurrence, and the remaining 16 cases required three or more operations to eradicate disease and reconstruct the hearing mechanism. Thirty-five (63%) of 56 patients had a postoperative air-conduction threshold pure-tone average (PTA) within 10 dB of the best bone-conduction PTA; 91% were within 20 dB. Average speech reception threshold improved from 32 dB hearing level (HL) preoperatively to 20 dB HL postoperatively.

Child↗
PubMed1995

Neurotologic treatment of acquired cholesteatoma.

Although much has been written about the central nervous system infectious complications of otitis media, little has been written about intracranial extension of cholesteatoma in chronic otitis media. The records of 13 patients from the House Ear Clinic with chronic otitis media and cholesteatoma extending into the middle fossa and/or the posterior fossa are reviewed. Preoperatively, symptoms included hearing loss (100%), dizziness (61%), facial weakness (46%), and headache (31%). All 13 patients had previously undergone at least one mastoidectomy procedure for removal of cholesteatoma. The neurotologic approaches used included the middle fossa, translabyrinthine, and transcochlear operations. Eradication of cholesteatoma was accomplished with one neurotologic procedure, in 11 of 13 patients with two neurotologic procedures in one patient, and without surgery in one patient. Audiologic findings and facial nerve results are discussed.

Adolescent↗
PubMed1995

Consonant perception by users of Nucleus and Clarion multichannel cochlear implants.

A study was carried out to compare the consonant perceptions of five Nucleus multichannel cochlear implant users, five Clarion-CIS users, and four Clarion-CA users. All subjects were administered the Iowa Medical Consonant Recognition Test in the auditory-only condition. The groups averaged approximately 1 year of implant use at the time of testing, and the average age at implantation was 47 years for the Nucleus users, 60 years for the Clarion-CIS users, and 56 years for the Clarion-CA users. The percent-corrected scores for all three devices were variable and ranged from 34% to 84%, with each group averaging about 50% correct consonant recognition. Consonant feature information transmission was calculated for five features: manner of articulation, nasality, place of articulation, duration, and voicing. The highest information transmission in the Nucleus group was for the features of duration (71%), nasality (60%), and voicing (57%), which agrees with previous studies. The Clarion-CIS group had the highest information transmission for duration, place of articulation, manner of articulation, and nasality (50%, 29%, 28%, and 27%). The Clarion-CA group had the highest information transmission for the features voicing, place of articulation, and duration (41%, 40%, and 37%). This study indicates that the Clarion device may carry some acoustic information related to place of articulation, a feature that has not been found to be encoded well by other multichannel cochlear implants.

Adult↗
PubMed1994

Intralabyrinthine schwannomas.

Intralabyrinthine schwannomas are unusual tumors of the vestibule, cochlea, semicircular canals, or some combination of these three, which in the past have been reported as incidental findings at autopsy or surgery. We summarize eight cases of intralabyrinthine schwannomas diagnosed by magnetic resonance imaging at the House Ear Clinic during the past 3 years. We discuss the typical clinical presentation and treatment of cochlear vs. vestibular intralabyrinthine schwannomas.

Adolescent↗
PubMed1994

Ossiculoplasty in congenital hearing loss.

We have presented an extensive review of congenital ossicular anomalies. These deformities occur in combination with one another or as isolated problems with equal frequency. They are so rare that even the busiest otologists have limited clinical experience with them. The astute otologist will keep these facts in mind when assessing congenital middle ear problems in the office and in the operating room. Careful, detailed history taking may reveal the presence of familial conductive hearing loss or other congenital syndromes. Complete head and neck examination as well as observation of the extremities may provide clues to the otologic diagnosis. Microscopic examination of the ear reveals abnormalities of the tympanic membrane, malleus, and incus. Audiometric and radiologic evaluation augments physical examination. At surgery, the otologist must be prepared to perform a variety of possible surgical procedures, from traditional ossiculoplasty and stapedectomy to fenestration. Hearing aids are an option for patients with congenital ossicular anomalies, and the possibility of inoperability must be kept in mind; the patient must be prepared for this eventuality. Congenital ossicular anomalies present a challenge to the otologic surgeon, and their successful treatment, the greatest reward.

Child, Preschool↗
PubMed1994

Acoustic neuroma in pregnancy.

Acoustic neuroma in the pregnant patient has been described infrequently. The symptoms of acoustic neuroma can commence or worsen during the last 3 or 4 months of pregnancy. In women, acoustic tumors have been shown generally to be larger and more vascular, and some acoustic tumors contain estrogen receptors. This is a report of our management of two patients with acoustic neuroma who presented early in pregnancy. Surgery was delayed to the second trimester in each, to avoid spontaneous abortion. Both patients underwent translabyrinthine tumor removal at 18-19 weeks gestation, and each had an uncomplicated postoperative course. Examination of the tumor for estrogen receptors was performed for the second patient and was negative. Uncomplicated acoustic neuroma surgery can be performed in pregnant patients during the second trimester.

Adult↗
PubMed1993

Hearing preservation in bilateral acoustic neuroma surgery.

Patients with neurofibromatosis type 2 (NF2) develop bilateral acoustic neuromas, but preservation of hearing while achieving tumor removal may present several unique problems. Our philosophy regarding hearing preservation attempts in these cases has evolved over several decades. The outcome of hearing preservation surgery using the middle cranial fossa approach for 13 procedures in 10 patients with NF2 is presented. There were 12 total tumor removals and one partial tumor removal. Two ears retained good postoperative hearing, three had serviceable hearing, four had measurable hearing, and four had no measurable hearing. Both cases with tumors 2 cm or larger retained no hearing. For the 12 total tumor removals, the rate of hearing preservation was 67 percent. Of four total removals with long-term follow-up, two retained good or serviceable hearing. The rate of hearing preservation is similar to that found in our series of unilateral acoustic neuroma surgeries. Based on these findings, hearing preservation surgery is recommended for patients with NF2 who have acoustic neuromas 1.5 cm or smaller.

Adolescent↗
PubMed1986

Transient hilar lymphadenopathy due to bacterial endocarditis.

Transient hilar and mediastinal lymphadenopathy accompanying right-sided bacterial endocarditis without concurrent roentgenographically-demonstrable pulmonary parenchymal abnormalities has not, to our knowledge, been previously reported. The roentgenographic finding of hilar or mediastinal lymphadenopathy should not be considered incompatible with the diagnosis of bacterial endocarditis in the appropriate clinical setting. Possible mechanisms for the development of lymphadenopathy secondary to bacterial endocarditis are discussed.

Adult↗
PubMed1986

Vowel perception: experiments with a single-electrode cochlear implant.

We investigated vowel perception by 15 subjects using the single-electrode cochlear implant used at the House Ear Institute in Los Angeles. Subjects were postlingually deaf adults having histories of unsuccessful hearing aid use and a minimum of 6 to 12 months experience with the implant. Eleven American English vowels spoken by a male talker were tape recorded, digitized, analyzed, and controlled for the experiments. The stimuli were audio-recordings of both natural and loudness-matched vowels. Subjects rated the dissimilarity of both the naturally spoken and the loudness-matched vowels, and performed identification of the latter. Two normal-hearing subjects served as controls for the dissimilarity tasks. Multidimensional scaling, hierarchical clustering, and percent correct identification analyses were used to help determine the perceptual features used by the subjects in their judgments. Generally, the normal-hearing subjects took advantage of second formant (F2) frequency information. The cochlear-implant users relied primarily upon fundamental (F0) and first formant (F1) frequency information and demonstrated difficulty in vowel identification. No major differences were noted for the natural versus loudness-matched vowels. F2 information, requisite for accurate vowel recognition, did not correspond to any of the perceptual dimensions discerned in the results obtained from implant subjects.

Adult↗
PubMed1982

Auditory perceptions induced by low-frequency acoustic and electric stimulation.

A comparison was made between listeners' perceptions of low frequency (LF) acoustic and electric stimuli. One normal-hearing S participated, and 3 profoundly deaf pts with intracochlear electrode systems. All Ss described their auditory perceptions to pulsatile and sinusoidal stimuli from 5 to 60 c/s. LF acoustic and electric stimuli produced similar auditory perceptions; no tactual component was found to electrical stimuli, although tactual components have been reported for LF acoustic stimuli; and at 5 c/s perceptual differences were noted between pulsed and sinusoidal stimuli, differences believed to be related to the degree of neural synchrony elicited by the two types of stimulus. This study provides direct support for the theory that in normal listeners LF auditory perception is attributable to a neural volley mechanism.

Acoustic Stimulation↗
PubMed1977

Validation norms for speech discrimination scores of normal-hearing subjects in wide-band and in speech-spectrum noise at S/N 0 DB.

W-22 lists were given at 40 db re SRT with a Maico MA-24B audiometer and attachments to 20 normal-hearing adults in quiet and in combination with either wide-band or speech-spectrum noise at S/N = 0, monaurally by earphone and binaurally by loudspeaker(s). No systematic L-R differences were observed. DS in quiet by any condition was at or near 100%. Mean DS in noise by monaural earphone was 79.80 +/- 13.3 for wide-band noise and 54.7 +/- 12.7 for speech-spectrum noise. When speech and noise were from two different loudspeakers placed +/- 45 degrees from midline, DS was 90.8 +/- 9.5 for wide-band noise and 88.1 +/- 7.8 for speech-spectrum noise. When both speech and noise came from the same loudspeaker, DS was 79.10 +/- 10.3 for wide-band noise and 57.0 +/- 21.8 for speech-spectrum noise. These values are proposed as provisional norms for clinical facilities using these conditions and employing similar instrumentation.

Adult↗
PubMedDate not supplied

Features from normal and sensorineural listeners' nonsense syllable test errors.

Identification errors for initial consonants of consonants-vowels-consonants-vowels from lists A and B of the Nonsense Syllable Test were analyzed for 10 normal-hearing and 8 sensorineural hearing-impaired listeners. The Nonsense Syllable Test stimuli were presented binaurally through earphones at 6 increasing sensation levels. Listeners' verbal responses were recorded and transcribed, converted to symmetric confusion matrices, and submitted to analysis of individual differences scaling for symmetrical matrices. Results from 2- through 5-dimensional analyses revealed that voicing, place of articulation, frication, and sibilancy were the salient features used by both listener types in their perceptions of the initial consonants. Findings suggest that consideration of composition of the stimulus set is important when assessing a listener's response to specific speech discrimination tests.

Adult↗
PubMedDate not supplied

Comparison of promontory and cochlear implants within a single subject.

Audiometric pure tone, speech, and psychoacoustic data were obtained from a patient who had worn a promontory electrode for two years. Subsequently the promontory implant was replaced by a scala tympani electrode (cochlear implant) and testing was repeated. Warbled tone thresholds ranged from 52-68 dB SPL for the octave frequencies 250-8000 Hz with the cochlear implant (CI), and from 65-74 dB SPL with the promontory electrode (PE). Speech discrimination scores were better with the CI than with the PE, although performance on an environmental sounds test was slightly better with the PE. Smaller intensity difference limens (DLs) were obtained with the CI (1 dB) than with the PE (about 4 dB). Frequency discrimination was poor with both electrode systems. The CI provided better frequency DLs at 250, 500, and 1000 Hz; the PE produced better DLs at 2000 Hz. When the CI was combined with a hearing aid worn on the better implanted ear, performance improved over that with either prosthesis alone.

Aged↗